The need to monitor movement of fluids underground arises in different circumstances. One non-limiting example of such circumstances includes enhanced oil recovery (EOR), where fluid(s) is/are injected into the ground to either reduce the viscosity of and/or push the oil towards the extraction (production) wells. Examples of the injected-fluid based methodologies include what's referred to as waterflooding, CO2 flooding, steam-assisted gravity drainage or SAGD, cyclic steam stimulation (CSS or huff-and-puff), aquifer recharge, in-situ recovery of minerals, to name just a few. And yet the related art appears to be silent with respect to methods enabling the user to directly, in real time detect and monitor the movement of fluids at typical reservoir or aquifer depths. Indeed, a major not-yet-addressed challenge remaining in related art is to detect fluid flow and direction long before it reaches the extraction well, and to monitor such movement of the detected fluid with ease and without impediments throughout the entirety of its propagation from an injection well to an extraction or monitoring well, so as to avoid, for example, unnecessary contaminations of the areas neighboring or present at the path of the fluid propagation underground. Methods of the fluid-movement monitoring proposed by Dasgupta in U.S. Pat. No. 8,041,510, for example, are rather complex, because these methods—as claimed by Dasgupta—while relying on the use of microseismic approach (which allows for the detection of fractures in the ground as they occur as a result of, for example, hydraulic-fracturing, or detection of changes in the reservoir chamber as a result of absence of oil, or increase in water content), nevertheless require the presence of acoustic “noise” produced by the fluid flow to detect the movement of the fluid. Such requirement inevitably limits the applicability of the Dasgupta's methods, as a fluid flow in unrestricted or minimally-restricted areas of the ground is simply unlikely to produce to produce a seismic signal, thereby rendering this method practically ineffective. Related art also references another method, according to which chemical tracers are added to the injected fluid, followed by physical/chemical determination of the presence of such tracers at a chosen point of observation, such as a monitoring well. Understandably, such method can only be of use if and when the tracers finally arrive at a production or monitoring well. At the same time, this method cannot facilitate at all the detection of the fluid movement prior to tracer arrival, and the inference of the direction (or vector) of the fluid movement can be based only on the tangible observation of proportional arrival of tracers at multiple monitoring wells.
Therefore, there remains a need in methodology facilitating the observation of the movement of fluid underground (with a determination of both speed and direction) in real time, which could afford the user to anticipate and/or predict the arrival of the fluid to a chosen reference location.